Age-related differences in the morphology of the impedance cardiography signal

Figures

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  Fig. 1. ICG plotted as change in impedance (−ΔZ), the time-derivative of the impedance (−dZ/dt) together with ECG. The B point marks the aortic valve opening, the X point marks aortic valve closure, the Y point marks pulmonic valve closure and the O point marks the rapid ventricular filling wave. The distance from the ECG Q-point to the ICG B point is attributed to the pre-ejection period of the heart (TPE), and the ICG B-X distance is attributed to the left ventricular ejection time (TLVE). The figure is copied from Bernstein 2009 under the Wikimedia Commons license.

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  Fig. 2. ICG (−dZ/dt) waveforms for each beat, resampled to an even length of one second (gray lines). The ensemble averages for every individual and phase is shown in the thick black line with ±1 standard deviation in the dashed lines.

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  Fig. 3. The ensemble averages of −dZ/dt for each individual within each phase (colored lines). The mean of these curves is shown in the thick black lines (grand ensemble averages).

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  Fig. 4. The ensemble averages of −d2Z/dt2 for each individual within each phase (colored lines). The mean of these curves is shown in the thick black lines (grand ensemble averages).